This is the supplication which the Prophet ﷺ taught his grandson al-Ḥasan ibn ‘Alī to say either before or after the rukū’ in the Witr prayer. In the tarāwīḥ prayer during the second half of Ramaḍān, one may add further supplications to this as the companions used to do (see al-Albānī’s book ‘Qiyām Ramaḍān’ p. 31).

اللَّهُمَّ اهْدِنِي فِيمَنْ هدَيْتَ، وَعَافِنِي فِيمَنْ عَافَيْتَ، وَتَوَلَّنِي فِيمَنْ تَوَلَّيْتَ، وَبَارِكْ لِي فِيمَا أَعْطَيْتَ، وَقِنِي شَرَّ مَا قَضَيْتَ؛ فَإنَّكَ تَقْضِي وَلَا يُقْضَى عَلَيْكَ، وَإنَّهُ لَا يَذِلُّ مَنْ وَالَيْتَ، وَلَا يَعِزُّ مَنْ عَاديْتَ، تَبَارَكْتَ ربَّنا وتَعالَيْتَ، لَا مَنْجَى مِنْكَ إلَّا إلَيْكَ.

Allaahumma ihdinee fee-man hadayta, wa ‘aafinee fee-man ‘aafayta, wa tawallanee fee-man tawallayt, wa baarik lee fee-maa a’aṭayt, wa qinee sharra ma qaḍayt, fa-innaka taqḍee wa laa yuqḍaa ‘alayk, wa innahu laa yadhillu man waalayt, wa laa ya’izzu man ‘aadayt, tabaarakta rabbanaa wa ta’aalayt, laa manjaa minka illaa ilayk.

O Allāh, guide me with those You have guided, heal me with those You have healed, care for me with those You have cared for, bless me in what You have given, and protect me from the evil of what You have decreed. Indeed, You decree while no one decrees against You. Whomever You show loyalty towards will never be humiliated and whoever You show enmity towards will never be honoured. Blessed are You, our Lord, and You are exalted far above (any deficiencies). There is no shelter from You except with You.